[LEDE-DEV] [PATCH] dnsmasq: add IPv6 nameserver configuration in server mode

[Arjen de Korte]

When in ra server mode, configure nameservers passed in router
announcements from the dns value (which is already used by odhcpd).

This also fixes FS#677 by using the global IPv6 address of the router
instead of the link local address (if no nameservers are configured).

Signed-off-by: Arjen de Korte <build+lede at de-korte.org>
---
 package/network/services/dnsmasq/files/dnsmasq.init | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/package/network/services/dnsmasq/files/dnsmasq.init b/package/network/services/dnsmasq/files/dnsmasq.init
index 1a1941f1d7..7cad06407f 100644
--- a/package/network/services/dnsmasq/files/dnsmasq.init
+++ b/package/network/services/dnsmasq/files/dnsmasq.init
@@ -466,6 +466,7 @@ dhcp_add() {
 	config_get ra "$cfg" ra
 	config_get ra_management "$cfg" ra_management
 	config_get ra_preference "$cfg" ra_preference
+	config_get dns "$cfg" dns
 
 	# Put the router host name on this DHCP served interface address(es)
 	dhcp_this_host_add "$net" "$ifname" "$ADD_LOCAL_FQDN"
@@ -533,6 +534,15 @@ dhcp_add() {
 			xappend "--dhcp-range=$nettag$dhcp6range,constructor:$ifname,slaac,ra-names,$leasetime"
 			;;
 		esac
+
+		if [ -n "$dns" ]; then
+			dnss=""
+			for d in $dns; do append dnss "[$d]" ","; done
+		else
+			dnss="[::]"
+		fi
+
+		dhcp_option_append "option6:dns-server,$dnss" "$networkid"
 	fi
 
 	dhcp_option_add "$cfg" "$networkid"
-- 
2.12.2